package com.bootdo.common.utils;

import java.util.HashMap;
import java.util.Map;

public class Test {

    public static void main(String[] args){
       /* Map<String,Object> map = new HashMap<>();
        map.put(null,null);*/
      /*  Map m = Conllections
        System.out.print(map.get(null));*/
    }
}
